GuitarBud is a $29 adapter that allows you to plug a guitar right into an iPhone. How is that useful? Well if I ever learned to play that guitar in my closet, I could:

• Record riffs
• Tune the strings
• Play with realtime audio effects
• Share riffs in the cloud
• ...and all of this with direct line-in quality, with the help of a few apps

If there's one, single testament to the App Store's success, it's that a simple piece of hardware can immediately add so much extra functionality to the iPhone (because apps like Voice Memos, StompVox, Riff Raters and Guitar FX Deluxe already exist). But then again, if only the iPhone had a fatty 1/4-inch jack or two, we wouldn't even need the GuitarBud in the first place! [PRSCables via ShinyShiny via DVICE]